[PATCH] D39769: [llvm-objcopy] Add --strip-all option to remove all non-allocated sections but keep section header table

[Jake Ehrlich via Phabricator via llvm-commits]

jakehehrlich created this revision.

This change adds a slightly less extreme form of stripping than --strip-sections that keeps thr section header table (and consequently .shstrtab as well)


Repository:
  rL LLVM

https://reviews.llvm.org/D39769

Files:
  test/tools/llvm-objcopy/strip-all.test
  tools/llvm-objcopy/llvm-objcopy.cpp


Index: tools/llvm-objcopy/llvm-objcopy.cpp
===================================================================
--- tools/llvm-objcopy/llvm-objcopy.cpp
+++ tools/llvm-objcopy/llvm-objcopy.cpp
@@ -81,6 +81,8 @@
                                       cl::desc("Remove a specific section"));
 static cl::alias ToRemoveA("R", cl::desc("Alias for remove-section"),
                            cl::aliasopt(ToRemove));
+static cl::opt<bool> StripAll("strip-all",
+                              cl::desc("Removes non-allocated sections"));
 static cl::opt<bool> StripSections("strip-sections",
                                    cl::desc("Remove all section headers"));
 static cl::opt<bool>
@@ -169,6 +171,13 @@
       return OnlyKeepDWOPred(*Obj, Sec) || RemovePred(Sec);
     };
 
+  if (StripAll)
+    RemovePred = [RemovePred, &Obj](const SectionBase &Sec) {
+      if (&Sec == Obj->getSectionHeaderStrTab())
+        return false;
+      return RemovePred(Sec) || (Sec.Flags & SHF_ALLOC) == 0;
+    };
+
   if (StripSections) {
     RemovePred = [RemovePred](const SectionBase &Sec) {
       return RemovePred(Sec) || (Sec.Flags & SHF_ALLOC) == 0;
Index: test/tools/llvm-objcopy/strip-all.test
===================================================================
--- /dev/null
+++ test/tools/llvm-objcopy/strip-all.test
@@ -0,0 +1,27 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-objcopy --strip-all %t %t2
+# RUN: llvm-readobj -file-headers -sections %t2 | FileCheck %s
+
+!ELF
+FileHeader:
+  Class:           ELFCLASS64
+  Data:            ELFDATA2LSB
+  Type:            ET_REL
+  Machine:         EM_X86_64
+Sections:
+  - Name:            .bss
+    Type:            SHT_NOBITS
+    Flags:           [ SHF_ALLOC ]
+    AddressAlign:    0x0000000000000010
+    Size:            4
+  - Name:            .text
+    Type:            SHT_PROGBITS
+    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
+    AddressAlign:    0x0000000000000010
+    Size:            4
+
+# CHECK: SectionHeaderCount: 4
+
+# CHECK:      Name: .bss
+# CHECK:      Name: .text
+# CHECK:      Name: .shstrtab


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